Method of making axle housings



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METHOD OF MAKING AXLE HOUSINGS Filed July 15. 1931 INVENTOR RU DDLF'HHHTHEIME.=

' TTORNEY Patented Jan. 30, 1934 METHOD OF MAKING AXLE HOUSINGS RudolphH. Thorns, Cleveland, Ohio, assignor to Midland Steel Products Company,Cleveland, Ohio, a corporation of Ohio Application July 15, 1931. SerialNo. 550,843

'14 Claims. (Cl. 229-1531) This invention relates to new and usefulimprovements in axle housings and the method of making the same.

An important object of the invention is to provide a method by whichthese housings can be formed from tubular stock without increasing ordiminishing the original wall thickness thereof at any point, therebyproducing a housing having the requisite uniform wall thickness withattendant equal distribution of uniform strength and no weak spotsthroughout the length of the housing.

It has been proposed to work with stock or tubing having a diameter lessthan that required for the enlarged end, but this necessitatesenlargement of such end which is later formed into the gear housingportion, with consequent reduction in wall thickness, unless compensatedfor by simultaneous axial pressure upon opposite ends of the tubing, orswaging prior to expansion.

In order to avoid complications resulting from the aforesaid practice,it is proposed to work with oversize stock having a diameter, so large,that the necessity for the aforesaid additional working is eliminated.

By the herein described method it is possible to eliminate at least onestep of upsetting for each section of the housing, thereby resulting inincreased production of superior housings at less costs and which arenotso apt to open at the seams of welded stock during their manufacture.

Other objects and advantages of the invention will become apparentduring the course of the following disclosure.

' $5 In the accompanying drawing forming a part of the description andwherein like numerals are employed to designate like parts throughoutthe several views.

Figure 1 is a side elevation of a length of circu- 40 lar tubing fromwhich each section of the axle housing is formed.

Figure 2 is an and elevation of the same. Figure 3 is a side elevationof tubing after the first swaging operation, with one end thereof 46broken away to illustrate the increased wall thickness imparted to oneend of the tubing.

Figure 4 is alongitudinal section through the same section of tubingillustrating the first drawing operation.

Figure 5 is a similar view illustrating the second drawing operation.

Figure 6 is a side elevation of one section of the housing in apartially completed condition, and Figure 7 is a plan of an axle housingpractically completed by joining two sections of tubing formed inaccordance with the invention.

Referring now more specifically to the drawing, the numeral 10,designates a length of circular tubing which may be seamless or formedfrom strip rolled and welded longitudinally along a seam as at 11. Dueto the difference in cost of the two kinds of tubing, axle housings canbe formed at less cost from welded tubing and it has been found that theherein disclosed method a can be carried out with less likelihood ofopening the welded seam, than is the case with other methods of formingsuch axle housings.

Since it is preferable to carry out the process with heated stock, itmay be given the herein described treatment prior to any appreciable.loss of heat incidental to the formation of the stock into tubular form,thereby effecting a saving in the heating and handling of the stock.With the tubing in heated condition, one end 12, is hot swaged to reduceits diameter, increase its wall thickness and to provide an internalshoulder 13, for abutment with a shoulder 14, on a die punch 15,employed in the drawing operation. During this hot swaging operation itis impor- 8 tant to note that the original wall thickness of theremaining portion of the tubing has not been increased or decreased'andthat it remains thesame throughout all stages of the manufacture.

The reduced end 12 of the stock which is sub- 35 sequently formed into acircumferential radial flange 16, for the attachment of a brake apronthereto, is inserted through a female die 17,

after which the male die punch 15, is projected into the'enlarged end ofthe tubing and against the shoulder 13, thereof. Continued movement ofthe punch 15, axially of the tubing, causes elongation of the latterthrough the die 17, while still maintaining the original wall thicknessof the tubing at all points up to the swaged end. 5 This operation isstopped short of drawing the entire length of tubing through the diethereby resulting in the formation of a shoulder 18, at a point locateda distance from the enlarged end 19 thereof, sufllcient to allow forenough material, of original stock diameter and wall thickness, beingleft for the formation of an enlarged gear housing portion 20.

After this operation the tubing is subjected to a second drawingoperation through a' smaller die 21 with a male die punch 22. This punchis provided with a shoulder 23 for engagement with the shoulder 13 ofthe tubing, and when projected through the die, will further elongatethe tubing and draw the same down to a smaller 110 diameter as indicatedat 26 in Figure 5. It is important to note that this second drawingoperationi like the first, does not in any way alter the originalthickness of the walls of the tubing at any point and that it remainsuniform with the exception of course, of the previously swaged portion12. Drawing the tubing through this second die, results in the formationof a second shoulder 24, in proximity to the shoulder 18, both of whichare later merged into a flared portion 25, as will be presentlydescribed.

, The swaged end 12, is then enlarged as at 27 and upset to produce theannular thickened flange 16, to which may be secured, in any suitablemanner, the brake apron heretofore referred to. The opposite enlargedend 19 of the tubing is then flattened or rather compressed to give itsubstantially elliptical cross sectionafter which it is provided with apair of diametrically disposed longitudinally extending slots 28,thereby forming the enlarged end, for a substantial portion of itslength, into a pairof arms 29, arcuate in cross section. This bifurcatedend is then positioned in a female die for final snaping and the arms 29are bowed and spread apart into the arcuate semi-circular formationshown by a male die section. This causes the enlarged end 19 of thetubing to be formed with the arouated channeled gear housing portion 20normal to the longitudinal plane of the tubing and the shoulders 18 and24 are simultaneously merged into the flaring portion 25, as indicatedin Figure 7. From the foregoing it will be obvious that the originalwall thickness of the stock remains unchanged throughout these formingoperations, thereby resulting in the production of an axle housingsection which is of uniform strength throughout its length. Moreover,when welded tubing is used, the method does not cause such stress uponthe welded seam as would cause the same to split.

In order to complete an axle housing, two of these symmetrically formedcomplementary sections are placed in alignment with the arcuate gearhousing portions arranged with their edges '30 in abutment, which edgesare welded together as at 31, thereby forming a substantially one pieceaxle housing. The .axle housing is completed by attaching substantiallycircular plates, not shown, to opposite sides of the complementary gear"housing section 20 to form an enclosure for the differential gear unit.

It will be understood that the method is not to be limited to'thesequence of steps set forth in the specification or limited otherwisethan recited in the appended claims. For instance, the entire drawingmay be found possible in one drawing operation instead of two; or it maybe expeditious to form the gear housing portions while the tubing isbeing drawn, and again it may be desirable to form the bowed portion 27and flange 16 after the gear housing portion is formed, instead of priorto its formation. The essential factor is the maintenance of originalwall thickness of the axle housing section throughout its length withthe exception of its outer end at the enlargement 2'7 and flange 16which latter is left thickened to impart requisite strength for theattachment of the usual brake apron. When welded tubing is used insteadof seamless, it is desirable but not necessary to position the slots 28in a plane arranged at about 90 from the plane of the weld so as toreduce to a minim m. any possible stress upon the welded noaaoso seamduring the spreading formation of the gear housing portion.

I claim:

1. Method of forming axle housings consisting of swaging one end oftubular stock to increase its wall thickness while leaving the other endat its original size, reducing the diameter of the intermediate portionof the stock by drawing out said portion and maintaining the constantoriginal wall thickness throughout the stock up to the thickened end;bowing outwardly the thickened end and forming a flange thereon, andthen form- Ling said other end into a substantially forked portionhaving wall thickness no thinner than other portions of housing.

2. The method of forming axle housings consisting of swaging one end oftubular stock to increase its wall thickness while leaving its other endits original size, reducing the diameter of the intermediate portion ofthe stock while maintaining the constant original wall thicknessthroughout the stock up to the thickened end,

forming said other end into a gear housing portion, and then turning anannular radial flange on the swaged end of the stock.

3. The method of forming axle housings consisting of swaging one end oftubular stock to increase its wall thickness while leaving its other endat its original size, drawing out the intermediate portion of the stockto elongate and reduce its diameter while maintaining the constantoriginal wall thickness throughout the stock up to the swaged end,further drawing out said reduced portion to further elongate and reducethe primarily reduced portion while still maintaining the constantoriginal wall thickness of the stock up to the swaged end and to formanintermediate tapered portion, upsetting the swaged end of the stock toform an annular flange, and then forming the other end of the stock intoa gear housing portion.

4. The method of forming axle housings consisting of swaging one end oftubular stock having a longitudinally extending welded seam to increaseits wall thickness while leaving its other end at its original size,reducing the diameter of the intermediate portion of the stock whilemaintaining the constant original wall thickness throughout the stock upto the swaged end, slotting the other end of the tube in a plane normal125 to that of the welded seam, then forming said other end in a planeparallel to that of the welded seam intoa substantially forked portion,and

attaching the forked portions of two such sections together.

5. The method "of forming axle housings consisting in drawing out aportion of tubular stock while maintaining its original wall thicknessand while leaving oneend of the stock at its original size and wallthickness, slotting and spreading said end into a gear housing portion,and then I attaching the two gear housing portions of two such sectionstogether.

6. In a method of forming an axle housing section including reducingtubular stock up to a point adjacent one end to provide an enlarged end,flattening the enlarged end into substantially oval cross section,slotting said enlarged end from its free end inwardly to a pointadjacent the shoulder formed by the enlarged end to provide a pair ofarms, and spreading said arms apart and bending them into arcuate shape.

7. In a method of forming an axle housing section including providing atube with an en- 'larged end, flattening said end into substantially1,94a,oso

oval shaped cross section, slotting said enlarged end from its free endinwardly for a substantial distance to provide a pair of arms, andspreading said arms apart and bending them into arcuate shape.

8. In a method of forming axle housing sections, the steps of reducingthe diameter of the major portion of the length of tubing whilemaintaining substantially the wall thickness of the original tubing andwhile leaving one end of the stock at its original size and wallthickness and of sufiicient diameter to be unaffected in wall thicknessby subsequent operation, bifurcating said enlarged end at diametricallyopposite points from its free end inwardly for a substantial distance toprovide a pair of channeled arms, and spreading said arms apart andbending them into arcuate shape.

9. In a method of forming an axle housing section, the steps of reducingthe diameten o! the major length of a piece of tubing while maintainingtherein substantially constant original wall thickness to provide thetubing with an enlarged end and an intermediate shoulder, bifurcatingsaid enlarged end at diametrically opposite points from its free endinwardly a substantial distance to provide a pair of arms, and spreadingthe arms apart and subsequently forming the arms into arcuate shapewhile forming said shouldered portion into a gradually tapered portion.4

10. The method of forming axle housings consisting of swaging one end oftubular stock to increase its wall thickness while leaving its other endat its original size, drawing out the intermediate portion of the tubeto elongate and reduce its diameter while maintaining the wall thicknessconstant throughout the tube up to the thickened end, bowing outwardlythe thickened end and forming a flange thereon, and forming said otherend into a gear housing portion having wall thickness substantiallyequal to the original tube. 2

11. The method of forming axle housingsconsisting of swaging one end oftubular stock to increase its wall thickness and to provide a workingshoulder while leaving its other end at its original size, drawing outthe intermediate portion of the tube by engaging the shoulder toelongate and reduce the diameter of the tube while maintaining itsoriginal wall thickness constant throughout the stock up to thethickened substantially equal to end, bowing outwardly the thickened endand forming a flange thereon, and forming said other end into a gearhousing portion.

12. The method of forming axle housings consisting of swaging one end oftubular stock to increase its wall thickness and to provide a workingshoulder while leaving its other end at its original size, drawing out aportion of the tube by engaging the shoulder to elongate and reduce thediameter of the tube while maintaining its wall thickness constantthroughout the stock up to the thickened end, then further drawing outsaid reduced portion to further elongate and reduce the primarilyreduced portion while still maintaining the constant original wallthickness of the tube up to the thickened end, bowing outwardly thethickened end and forming a flange thereon, and then forming said otherend into a gear housing portion.

13. The method of forming axle housings consisting of swaging one end oftubular stock to increase its wall thickness and to provide a workingshoulder while leaving one end its original size, drawing out a portionof the stock by exerting thrust on said shoulder to elongate and reducethe diameter of the tube while maintaining its original wall thicknessup to the thickened end, bowing outwardly the thickened end and forminga flange thereon, and then forming the other end having original tubediameter and thickness into a substantially forked end portion havingwall thickness substantially equal to the original stock. Y

14. The method of forming axle housings consisting of swaging one end oftubular stock to increase its wall thickness and to provide a workingshoulder for a punch while leaving one end its original size, drawingout a portion of the stock by exerting thrust onv said shoulder toelongate and reduce the diameter of the tube while maintainingsubstantially its original wallthickness throughout the stock up to thethickened end, then further drawing 'out said reduced portion to furtherelongate and reduce the primarily reduced portion while maintainingsubstantially constant original wall thickness of the stock up to thethickened end, expanding the thickened end and forming a flange thereon,and then forming the other end having original stock diameter into asubstantially forked portion having wallthickness the original stock.

RUDOLPH H. THOMS.

